Articulate and swapable endoscope for a surgical robot

ABSTRACT

The present invention is directed to an articulate minimally invasive surgical endoscope with a flexible wrist having at least one degree of freedom. When used with a surgical robot having a plurality of robot arms, the endoscope can be used with any of the plurality of arms thereby allowing the use a universal arm design. The endoscope in accordance to the present invention is made more intuitive a to a user by attaching a reference frame used for controlling the at least one degree of freedom motion to the flexible wrist for wrist motion associated with the at least one degree of freedom. The endoscope in accordance to the present invention attenuates undesirable motion at its back/proximal end by acquiring the image of the object in association with the at least one degree of freedom based on a reference frame rotating around a point of rotation located proximal to the flexible wrist.

RELATED U.S. APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.11/319,011, which is a continuation-in-part of patent application withSer. No. 11/071,480 filed Mar. 3, 2005, which is a continuation-in-partof patent application with Ser. No. 10/726,795 filed Dec. 2, 2003, nowU.S. Pat. No. 7,320,700, which claims priority from provisionalapplication No. 60/431,636 filed on Dec. 6, 2002. U.S. patentapplication Ser. No. 11/319,011 is also a continuation-in-part of patentapplication with Ser. No. 10/980,119 filed Nov. 1, 2004, now U.S. Pat.No. 7,736,356, which is a divisional of U.S. patent application Ser. No.10/187,248, now U.S. Pat. No. 6,817,974, issued on Nov. 16, 2004 whichclaims priority from provisional application No. 60/301,967 filed onJun. 29, 2001 and provisional application No. 60/327,702, filed on Oct.5, 2001.

-   U.S. Pat. No. 6,699,235, entitled “Platform Link Wrist Mechanism”,    issued on Mar. 2, 2004;-   U.S. Pat. No. 6,786,896, entitled “Robotic Apparatus”, issued on    Sep. 7, 2004;-   U.S. Pat. No. 6,331,181, entitled “Surgical Robotic Tools, Data    Architecture, and Use”, issued on Dec. 18, 2001;-   U.S. Pat. No. 6,799,065, entitled “Image Shifting Apparatus and    Method for a Telerobotic System”, issued on Sep. 28, 2004;-   U.S. Pat. No. 6,720,988, entitled “Stereo Imaging System and Method    for Use in Telerobotic System”, issued on Apr. 13, 2004;-   U.S. Pat. No. 6,714,839, entitled “Master Having Redundant Degrees    of Freedom”, issued on Mar. 30, 2004;-   U.S. Pat. No. 6,659,939, entitled “Cooperative Minimally Invasive    Telesurgery System”, issued on Dec. 9, 2003;-   U.S. Pat. No. 6,424,885, entitled “Camera Referenced Control in a    Minimally Invasive Surgical Apparatus”, issued on Jul. 23, 2002;-   U.S. Pat. No. 6,394,998, entitled “Surgical Tools for Use in    Minimally Invasive Telesurgical Applications”, issued on May 28,    2002; and-   U.S. Pat. No. 5,808,665, entitled “Endoscopic Surgical Instrument    and Method for Use”, issued on Sep. 15, 1998; and-   U.S. Pat. No. 5,808,665, entitled “Endoscopic Surgical Instrument    and Method for Use”, issued on Sep. 15, 1998; and-   U.S. Pat. No. 6,522,906, entitled “Devices and Methods for    Presenting and Regulating Auxiliary Infoiivation on An Image Display    of a Telesurgical System to Assist an Operator in Performing a    Surgical Procedure”, issued on Feb. 18, 2003.-   U.S. Pat. No. 6,364,888 entitled “Alignment of Master and Slave in a    Minimally Invasive Surgical Apparatus”, issued on Apr. 2, 2002.

BACKGROUND OF THE INVENTION

The present invention relates generally to endoscopes and, moreparticularly, to steerable/articulate and swappable endoscopes forperforming robotic surgery.

Advances in minimally invasive surgical technology could dramaticallyincrease the number of surgeries performed in a minimally invasivemanner. Minimally invasive medical techniques are aimed at reducing theamount of extraneous tissue that is damaged during diagnostic orsurgical procedures, thereby reducing patient recovery time, discomfort,and deleterious side effects. The average length of a hospital stay fora standard surgery may also be shortened significantly using minimallyinvasive surgical techniques. Thus, an increased adoption of minimallyinvasive techniques could save millions of hospital days, and millionsof dollars annually in hospital residency costs alone. Patient recoverytimes, patient discomfort, surgical side effects, and time away fromwork may also be reduced with minimally invasive surgery.

The most common form of minimally invasive surgery may be endoscopy.Probably the most common form of endoscopy is laparoscopy, which isminimally invasive inspection and surgery inside the abdominal cavity.In standard laparoscopic surgery, a patient's abdomen is insufflatedwith gas, and cannula sleeves are passed through small (approximately ½inch) incisions to provide entry ports for laparoscopic surgicalinstruments. The laparoscopic surgical instruments generally include alaparoscope (for viewing the surgical field) and working tools. Theworking tools are similar to those used in conventional (open) surgery,except that the working end or end effector of each tool is separatedfrom its handle by an extension tube. As used herein, the term “endeffector” means the actual working part of the surgical instrument andcan include clamps, graspers, scissors, staplers, and needle holders,for example. To perform surgical procedures, the surgeon passes theseworking tools or instruments through the cannula sleeves to an internalsurgical site and manipulates them from outside the abdomen. The surgeonmonitors the procedure by means of a monitor that displays an image ofthe surgical site taken from the laparoscope. Similar endoscopictechniques are employed in, e.g., arthroscopy, retroperitoneoscopy,pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy,hysteroscopy, urethroscopy and the like.

There are many disadvantages relating to current minimally invasivesurgical (MIS) technology. For example, existing MIS instruments denythe surgeon the flexibility of tool placement found in open surgery.Most current laparoscopic tools have rigid shafts, so that it can bedifficult to approach the worksite through the small incision.Additionally, the length and construction of many endoscopic instrumentsreduces the surgeon's ability to feel forces exerted by tissues andorgans on the end effector of the associated tool. The lack of dexterityand sensitivity of endoscopic tools is a major impediment to theexpansion of minimally invasive surgery.

Minimally invasive telesurgical robotic systems are being developed toincrease a surgeon's dexterity when working within an internal surgicalsite, as well as to allow a surgeon to operate on a patient from aremote location. In a telesurgery system, the surgeon is often providedwith an image of the surgical site at a computer workstation. Whileviewing a three-dimensional image of the surgical site on a suitableviewer or display, the surgeon performs the surgical procedures on thepatient by manipulating master input or control devices of theworkstation. The master controls the motion of a servomechanicallyoperated surgical instrument. During the surgical procedure, thetelesurgical system can provide mechanical actuation and control of avariety of surgical instruments or tools having end effectors such as,e.g., tissue graspers, needle drivers, or the like, that perform variousfunctions for the surgeon, e.g., holding or driving a needle, grasping ablood vessel, or dissecting tissue, or the like, in response tomanipulation of the master control devices.

While minimally invasive surgical robotic systems such as the da Vinci®from Intuitive Surgical Inc. of Sunnyvale, Calif. can provide surgeonswith much more articulation and much improved quality 2D and 3D videoimages during surgeries than conventional laparoscopy, currently suchsurgical robotic systems may be more limited in terms of flexibility incertain functions. In particular, due to their size and weight, asurgical robot architecture with a “dedicated” robot arm is required tohold the endoscope and its camera heard such as that described in U.S.Pat. No. 6,451,027. As a result, surgeons cannot exchange the endoscopebetween ports as typically occurred in conventional laparoscopy.Moreover, the size and weight of the endoscope causes difficulty indismounting and manually maneuvering the endoscope especially to seedifficult-to-reach or hidden areas. This loss of flexibility means thatwhile minimally invasive surgical robotic systems excel in difficultreconstructive surgeries in confined areas such as the heart and pelvis,they become less applicable for procedures involving access to largeanatomical areas (e.g., multiple quadrants of the abdomen) and/or accessfrom different directions.

Furthermore, current robotic endoscopes are rigid, pointing eitherstraight ahead (i.e., zero (0) degree angle) or at a thirty (30) degreeangle from the long axis of the endoscope which allows the surgeon tomore easily look down or up. Consequently, during many surgicalprocedures, the surgeon may require to switch back and forth numeroustimes between a straight ahead scope and a thirty-degree scope to obtaindifferent perspectives inside the surgical site. Such scope switchingincreases the surgical procedure's duration, operational and logisticcomplexity, and even safety concerns. However, even with scopeswitching, the surgeon is still limited to only a few visualperspectives and therefore a smaller area of visibility. Additionally,the surgeon may yet be prevented from getting a desired view of the bodytissues that are hidden around obstacles (e.g., during gynecologicalprocedures) or between tissue that requires some tunneling (e.g., duringatrial fibrillation or endoluminal diagnosis and treatment).

Thus, a need exists for a surgical robotic endoscope system and methodthat allows for simplification of future surgical robot architectures,provides more flexible port placement, provides a greater area ofvisibility, provide multiple visual perspectives without addedoperational and logistic complexity or safety concerns, and provides themost desirable view of hidden body tissues.

BRIEF SUMMARY OF THE INVENTION

Accordingly, the present invention provides an articulate and swappablesurgical robotic endoscope system and method that allows forsimplification of future surgical robot architectures, provides moreflexible port placement, provides a greater area of visibility, providemultiple visual perspectives without added operational and logisticcomplexity or safety concerns, and provides the most desirable view ofhidden body tissues.

The present invention meets the above need with a minimally invasivearticulate surgical endoscope comprising an elongate shaft, a flexiblewrist, an endoscopic camera lens, and a plurality of actuation links.The elongate shaft has a working end, a proximal end, and a shaft axisbetween the working end and the proximal end. The flexible wrist has adistal end and a proximal end. The proximal end of the wrist isconnected to the working end of the elongate shaft. The endoscopiccamera lens is installed at the distal end of the wrist. The pluralityof actuation links are connected between the wrist and the proximal endof the elongate shaft such that the links are actuatable to provide thewrist with at least one degree of freedom (e.g., both wrist pitching andyawing motions) wherein a reference frame used for controlling the atleast one degree of freedom motion is attached to the flexible wrist forwrist motion associated with the at least one degree of freedom toprovide more intuitiveness to the user during the at least one degree offreedom motion. Conversely, the reference frame used for controllingother degrees of freedom (e.g., Cartesian space insertion/extractionmotion and shaft rotation) associated with the endoscope is attached tothe object. The minimally invasive articulate surgical endoscope isreleaseably coupled to any of the plurality of arms and is designed tobe swapped between the plurality of arms such that one standard armdesign is used for the surgical robotic system.

When the articulate surgical endoscope is used to acquire an image(e.g., an orbital image) of an anatomy in association with the at leastone degree of freedom, the reference frame for such image is one thatrotates around a point of rotation located proximal to the flexiblewrist to minimize undesirable motion at the proximal end of theendoscope. Such undesirable motion is further attenuated when thereference frame used for controlling the at least one degree of freedomis attached to the flexible wrist.

All the features and advantages of the present invention will becomeapparent from the following detailed description of its preferredembodiments whose description should be taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of a surgical tool according to an embodiment ofthe invention.

FIG. 2 is a cross-sectional view of a wrist according to an embodimentof the present invention.

FIG. 3 is cross-sectional view of the wrist of FIG. 2 along III-III.

FIG. 4 is a perspective view of a wrist according to another embodimentof the invention.

FIGS. 4A and 4B are, respectively, a plan view and an elevation view ofa distal portion of an example of a wrist similar to that of FIG. 4,showing details of the cable arrangement.

FIG. 5 is a perspective view of a wrist according to another embodimentof the invention.

FIG. 6 is a plan view of a wrist according to another embodiment of theinvention;

FIG. 7 is a cross-sectional view of a wrist according to anotherembodiment of the invention.

FIG. 8 is a plan view of a wrist according to another embodiment of theinvention.

FIG. 9 is an elevational view of the wrist of FIG. 8 with a tool shaftand a gimbal plate.

FIG. 10 is a plan view of a wrist according to another embodiment of theinvention;

FIG. 11 is an elevational view of the wrist of FIG. 10.

FIG. 12 is an elevational view of a wrist according to anotherembodiment of the invention.

FIG. 13 is a plan view of a wrist according to another embodiment of theinvention.

FIG. 14 is a cross-sectional view of a portion of a wrist according toanother embodiment of the invention.

FIG. 15 is a partial sectional view of the wrist of FIG. 14 in bending.

FIG. 16 is a perspective view of a wrist according to another embodimentof the invention.

FIG. 17 is a plan view of the wrist of FIG. 16.

FIG. 18 is a cross-sectional view of a portion of a wrist according toanother embodiment of the invention.

FIG. 19 is a perspective view of a wrist according to another embodimentof the invention.

FIG. 20 is a plan view of a wrist according to another embodiment of theinvention.

FIG. 21 is a perspective view of a wrist according to another embodimentof the invention.

FIG. 22 is a cross-sectional view of a portion of a wrist according toanother embodiment of the invention.

FIGS. 23 and 24 are plan views of the disks in the wrist of FIG. 22.

FIG. 25 is a perspective view of an outer piece for the wrist of FIG.22.

FIG. 26 is a cross-sectional view of the outer piece of FIG. 25.

FIG. 27 is a perspective view of a wrist according to another embodimentof the invention.

FIG. 28 is an cross-sectional view of a wrist cover according to anembodiment of the invention.

FIG. 29 is an cross-sectional view of a wrist cover according to anotherembodiment of the invention.

FIG. 30 is a perspective view of a portion of a wrist cover according toanother embodiment of the invention.

FIG. 31 illustrates an embodiment of an articulate endoscope used inrobotic minimally invasive surgery in accordance with the presentinvention.

FIG. 32 illustrates catheter 321 releasably coupled to endoscope 310 bya series of releasably clips 320.

FIG. 33 illustrates catheter guide 331 releasably coupled to endoscope310 by a series of releasably clips 320.

FIG. 34 is a video block diagram illustrating an embodiment of the videoconnections in accordance to the present invention.

FIG. 35 illustrates an embodiment of an articulate endoscope used inrobotic minimally invasive surgery in accordance with the presentinvention.

FIG. 36 is a simplistic exemplary illustration of intuitive versuscounter-intuitive relative to different frames of reference for arobotic minimally invasive endoscope.

FIG. 37 illustrates the different potential points of rotation forendoscope 310″ in accordance to the present invention

FIG. 38 illustrates the two master input devices virtually combined tooperate in a similar fashion to a bicycle handle bar

DETAILED DESCRIPTION OF THE INVENTION

As used herein, “end effector” refers to an actual working distal partthat is manipulable by means of the wrist member for a medical function,e.g., for effecting a predetermined treatment of a target tissue. Forinstance, some end effectors have a single working member such as ascalpel, a blade, or an electrode. Other end effectors have a pair orplurality of working members such as forceps, graspers, scissors, orclip appliers, for example. In certain embodiments, the disks orvertebrae are configured to have openings which collectively define alongitudinal lumen or space along the wrist, providing a conduit for anyone of a number of alternative elements or instrumentalities associatedwith the operation of an end effector. Examples include conductors forelectrically activated end effectors (e.g., electrosurgical electrodes;transducers, sensors, and the like); conduits for fluids, gases orsolids (e.g., for suction, insufflation, irrigation, treatment fluids,accessory introduction, biopsy extraction and the like); mechanicalelements for actuating moving end effector members (e.g., cables,flexible elements or articulated elements for operating grips, forceps,scissors); wave guides; sonic conduction elements; fiberoptic elements;and the like. Such a longitudinal conduit may be provided with a liner,insulator or guide element such as a elastic polymer tube; spiral wirewound tube or the like.

As used herein, the terms “surgical instrument”, “instrument”, “surgicaltool”, or “tool” refer to a member having a working end which carriesone or more end effectors to be introduced into a surgical site in acavity of a patient, and is actuatable from outside the cavity tomanipulate the end effector(s) for effecting a desired treatment ormedical function of a target tissue in the surgical site. The instrumentor tool typically includes a shaft carrying the end effector(s) at adistal end, and is preferably servomechanically actuated by atelesurgical system for performing functions such as holding or drivinga needle, grasping a blood vessel, and dissecting tissue.

The various embodiments of the flexible wrist described herein areintended to be relatively inexpensive to manufacture and be capable ofuse for cautery, although they are not limited to use for cautery. ForMIS applications, the diameter of the insertable portion of the tool issmall, typically about 12 mm or less, and preferably about 5 mm or less,so as to permit small incisions. It should be understood that while theexamples described in detail illustrate this size range, the embodimentsmay be scaled to include larger or smaller instruments.

Some of the wrist embodiments employ a series of disks or similarelements that move in a snake-like manner when bent in pitch and yaw(e.g., FIGS. 14 and 22). The disks are annular disks and may havecircular inner and outer diameters. Typically, those wrists each includea series of disks, for example, about thirteen disks, which may be about0.005 inch to about 0.030 inch thick, etched stainless steel disks.Thinner disks may be used in the middle, while thicker disks aredesirable for the end regions for additional strength to absorb cableforces such as those that are applied at the cable U-turns around theend disk. The end disk may include a counter bore (e.g., about 0.015inch deep) into which the center spring fits to transfer the load fromthe cables into compression of the center spring. The disks may bethreaded onto an inner spring, which acts as a lumen for pulling cablesfor an end effector such as a gripper, a cautery connection, or a tetherto hold a tip thereon. The inner spring also provides axial stiffness,so that the gripper or tether forces do not distort the wrist. In someembodiments, the disks include a pair of oppositely disposed inner tabsor tongues which are captured by the inner spring. The inner spring isat solid height (the wires of successive helix pitches lie in contactwith one another when the spring is undeflected), except at places wherethe tabs of the disks are inserted to create gaps in the spring. Thedisks alternate in direction of the tabs to allow for alternating pitchand yaw rotation. A typical inner spring is made with a 0.01 inchdiameter wire, and adjacent disks are spaced from one another by fourspring coils. If the spring is made of edge wound flat wire (like aslinky), high axial force can be applied by the cables without causingneighboring coils to hop over each other.

In some embodiments, each disk has twelve evenly spaced holes forreceiving actuation cables. Three cables are sufficient to bend thewrist in any desired direction, the tensions on the individual cablesbeing coordinated to produce the desired bending motion. Due to thesmall wrist diameter and the moments exerted on the wrist by surgicalforces, the stress in the three cables will be quite large. More thanthree cables are typically used to reduce the stress in each cable(including additional cables which are redundant for purposes ofcontrol). In some examples illustrated below, twelve or more cables areused (see discussion of FIG. 4 below). To drive the cables, a gimbalplate or rocking plate may be used. The gimbal plate utilizes twostandard inputs to manipulate the cables to bend the wrist at arbitraryangles relative to the pitch and yaw axes.

Some wrists are fowled from a tubular member that is sufficientlyflexible to bend in pitch and yaw (e.g., FIGS. 2 and 4). An inner springmay be included. The tubular member may include cut-outs to reduce thestructural stiffness to facilitate bending (e.g., FIGS. 5 and 19). Oneway to make the wrist is to insert wire and hypotube mandrels in thecenter hole and the actuation wire holes. A mold can be made, and theassembly can be overmolded with a two-part platinum cure silicone rubbercured in the oven (e.g., at about 165° C.). The mandrels are pulled outafter molding to create channels to form the center lumen and peripherallumens for the pulling cables. In this way, the wrist has no exposedmetal parts. The rubber can withstand autoclave and can withstand theelongation during wrist bending, which is typically about 30% strain.

In specific embodiments, the tubular member includes a plurality ofaxial sliding members each having a lumen for receiving an actuationcable (e.g., FIG. 8). The tubular member may be formed by a plurality ofaxial springs having coils which overlap with the coils of adjacentsprings to provide lumens for receiving the actuation cables (e.g., FIG.10). The tubular member may be formed by a stack of wave springs (e.g.,FIG. 12). The lumens in the tubular member may be formed by interiors ofaxial springs (e.g., FIG. 16). The exterior of the tubular member may bebraided to provide torsional stiffness (e.g., FIG. 27).

A. Wrist Having Wires Supported by Wire Wrap

FIG. 1 shows a wrist 10 connected between a distal end effector 12 and aproximal tool shaft or main tube 14 for a surgical tool. The endeffector 12 shown includes grips 16 mounted on a distal clevis 18, asbest seen in FIG. 2. The distal clevis 18 includes side access slots 20that house distal crimps 22 of a plurality of wires or cables 24 thatconnect proximally to hypotubes 26, which extend through a platform orguide 30 and the interior of the tool shaft 14. The guide 30 orients thehypotubes 26 and wire assembly, and is attached the tool shaft 14 of theinstrument. The guide 30 also initiates the rolling motion of the wrist10 as the tool shaft 14 is moved in roll. The side access slots 20conveniently allow the crimps 22 to be pressed into place. Of course,other ways of attaching the wires 24 to the distal clevis 18, such aslaser welding, may be employed in other embodiments.

FIGS. 2 and 3 show four wires 24, but a different number of wires may beused in another embodiment. The wires 24 may be made of nitinol or othersuitable materials. The wires 24 create the joint of the wrist 10, andare rigidly attached between the distal clevis 18 and the hypotubes 26.A wire wrap 34 is wrapped around the wires 24 similar to a coil springand extends between the distal clevis 18 and the hypotubes 26. Theshrink tube 36 covers the wire wrap 34 and portions of the distal clevis18 and the guide 30. The wire wrap 34 and shrink tube 36 keep the wires24 at fixed distances from each other when the hypotubes 26 are pushedand pulled to cause the wrist 10 to move in pitch and yaw. They alsoprovide torsional and general stiffness to the wrist 10 to allow it tomove in roll with the tool shaft 14 and to resist external forces. Thewire wrap and shrink tube can be configured in different ways in otherembodiments (one preferred embodiment is shown in FIG. 27 and describedin Section J below). For example, they can be converted into afive-lumen extrusion with the wires 24 as an internal part. The functionof the wire wrap or an equivalent structure is to keep the wires 24 at aconstant distance from the center line as the wrist 10 moves in roll,pitch, and/or yaw. The shrink tube can also provide electricalisolation.

B. Wrist Having Flexible Tube Bent by Actuation Cables

FIG. 4 shows a wrist 40 that includes a tube 42 having holes or lumens43 distributed around the circumference to receive actuation cables orwires 44, which may be made of nitinol. The tube 42 is flexible topermit bending in pitch and yaw by pulling the cables 44. The wrist 40preferably includes a rigid distal termination disk 41 (as shown in analternative embodiment of FIG. 4B) or other reinforcement that issubstantially more rigid than the flexible tube 42 to evenly distributecable forces to the flexible tube 42. The hollow center of the tube 42provides room for end effector cables such as gripping cables. There aretypically at least four lumens. An inner spring 47 may be provided.

FIG. 4 shows twelve lumens for the specific embodiment to accommodatesix cables 44 making U-turns 45 at the distal end of the tube 42. Thehigh number of cables used allows the tube 42 to have a higher stiffnessfor the same cable pulling force to achieve the same bending in pitchand yaw. For example, the use of twelve cables instead of four cablesmeans the tube 42 can be three times as stiff for the same cable pullingforce. Alternatively, if the stiffness of the tube 42 remains the same,the use of twelve cables instead of four cables will reduce the cablepulling force required by a factor of three. Note that although thematerial properties and cable stress levels may permit the U-turns 45 tobear directly on the end of the tube 42, a reinforced distal terminationplate 41 may be included to distribute cable forces more smoothly overthe tube 42. The proximal ends of the cables 44 may be connected to anactuator mechanism, such as an assembly including a gimbal plate 46 thatis disclosed in U.S. patent application Ser. No. 10/187,248, filed onJun. 27, 2002, the full disclosure of which is incorporated herein byreference. This mechanism facilitates the actuation of a selectedplurality of cables in a coordinated manner for control of a bendable orsteerable member, such as controlling the flexible wrist bending angleand direction. The example of an actuator mechanism of application Ser.No. 10/187,248 can be adapted to actuate a large number of peripheralcables in a proportionate manner so as to provide a coordinated steeringof a flexible member without requiring a comparably large number oflinear actuators. Alternatively, a separately controlled linearactuation mechanism may be used to tension each cable or cable pairslooped over a pulley and moved with a rotary actuator, the steeringbeing controlled by coordinating the linear actuators.

The tube 42 typically may be made of a plastic material or an elastomerwith a sufficiently low modulus of elasticity to permit adequate bendingin pitch and yaw, and may be manufactured by a multi-lumen extrusion toinclude the plurality of lumens, e.g., twelve lumens. It is desirablefor the tube to have a high bending stiffness to limit undesirabledeflections such as S-shape bending, but this increases the cable forcesneeded for desirable bending in pitch and yaw. As discussed below, onecan use a larger number of cables than necessary to manipulate the wristin pitch and yaw (i.e., more than three cables) in order to providesufficiently high cable forces to overcome the high bending stiffness ofthe tube.

FIGS. 4A and 4B show schematically an example of two different cablearrangements in a wrist embodiment similar to that shown in FIG. 4. Notethat for constant total cable cross-sectional area, including cables inpairs and including a greater number of proportionately smaller cablesboth permit the cables to terminate at a greater lateral offset relativeto the wrist centerline. FIGS. 4A and 4B show a plan view and anelevational view respectively of a wrist embodiment, split by a dividingline such that the right side of each figure shows a wrist Example 1,and the left side of each figure shows a wrist Example 2. In eachexample the tube 42 has the same outside radius R and inside radius rdefining the central lumen.

In Example 1, the number of cables 44 in the wrist 40.1 is equal to four(n1=4) with each cable individually terminated by a distal anchor 44.5,set in a countersunk bore in the distal termination plate 41, each cableextending through a respective lateral cable lumen 43 in the distaltermination plate 41 and the flexible tube 42. The anchor 44.5 may be aswaged bead or other conventional cable anchor.

In Example 2, the number of cables 44′ in the wrist 40.2 is equal tosixteen (n2=16), with the cables arranged as eight symmetrically spacedpairs of portions 44′, each pair terminated by a distal “U-turn” endloop 45 bearing on the distal termination plate 41′ between adjacentcable lumens 43′. The edges of the distal termination plate 41′ at theopening of lumens 43′ may be rounded to reduce stress concentration, andthe loop 45 may be partially or entirely countersunk into the distaltermination plate 41. The diameters of the sixteen cables 44′ are ½ thediameters of the four cables 44, so that the total cross-sectional cablearea is the same in each example.

Comparing Examples 1 and 2, the employment of termination loop 45eliminates the distal volume devoted to a cable anchor 44.5, and tendsto permit the cable lumen 43′ to be closer to the radius R of the tube42 than the cable lumen 43. In addition, the smaller diameter of eachcable 44′ brings the cable centerline closer to the outer edge of thecable lumen 43′. Both of these properties permit the cables in Example 2to act about a larger moment arm L2 relative to the center of tube 42than the corresponding moment arm L1 of Example 1. This greater momentarm L2 permits lower cable stresses for the same overall bending momenton the tube 42 (permitting longer cable life or a broader range ofoptional cable materials), or alternatively, a larger bending moment forthe same cable stresses (permitting greater wrist positioningstiffness). In addition, smaller diameter cables may be more flexiblethan comparatively thicker cables. Thus a preferred embodiment of thewrist 40 includes more that three cables, preferably at least 6 (e.g.,three pairs of looped cables) and more preferably twelve or more.

Note that the anchor or termination point shown at the distaltermination plate 41 is exemplary, and the cables may be terminated (byanchor or loop) to bear directly on the material of the tube 42 if theselected material properties are suitable for the applied stresses.Alternatively, the cables may extend distally beyond the tube 42 and/orthe distal termination plate 41 to terminate by connection to a moredistal end effector member (not shown), the cable tension beingsufficiently biased to maintain the end effector member securelyconnected to the wrist 40 within the operational range of wrist motion.

One way to reduce the stiffness of the tube structurally is to providecutouts, as shown in FIG. 5. The tube 50 includes a plurality of cutouts52 on two sides and alternating in two orthogonal directions tofacilitate bending in pitch and yaw, respectively. A plurality of lumens54 are distributed around the circumference to accommodate actuationcables.

In another embodiment illustrated in FIG. 6, the tube 60 is formed as anouter boot wrapped around an interior spring 62 which is formed of ahigher stiffness material than that for the tube 60. The tube 60includes interior slots 64 to receive actuation cables. Providing aseparately formed flexible tube can simplify assembly. Such a tube iseasier to extrude, or otherwise form, than a tube with holes for passingthrough cables. The tube also lends itself to using actuation cableswith preformed termination structures or anchors, since the cables canbe put in place from the central lumen, and then the inner springinserted inside the cables to maintain spacing and retention of thecables. In some cases, the tube 60 may be a single use component that issterile but not necessarily autoclavable.

FIG. 7 shows a tube 70 having cutouts 72 which may be similar to thecutouts 52 in the tube 50 of FIG. 5. The tube 70 may be made of plasticor metal. An outer cover 74 is placed around the tube 50. The outercover 74 may be a Kapton cover or the like, and is typically a highmodulus material with wrinkles that fit into the cutouts 72.

C. Wrist Having Axial Tongue and Groove Sliding Members

FIGS. 8 and 9 show a wrist 80 having a plurality of flexible, axiallysliding members 82 that are connected or interlocked to each other by anaxial tongue and groove connection 84 to form a tubular wrist 80. Eachsliding member 82 forms a longitudinal segment of the tube 80. The axialconnection 84 allows the sliding members 82 to slide axially relative toeach other, while maintaining the lateral position of each memberrelative to the wrist longitudinal centerline. Each sliding member 82includes a hole or lumen 86 for receiving an actuation cable, which isterminated adjacent the distal end of the wrist 80. FIG. 9 illustratesbending of the wrist 80 under cable pulling forces of the cables 90 asfacilitated by sliding motion of the sliding members 82. The cables 90extend through the tool shaft 92 and are connected proximally to anactuation mechanism, such as a gimbal plate 94 for actuation. Thesliding members 82 bend by different amounts due to the difference inthe radii of curvature for the sliding members 82 during bending of thewrist 80. Alternatively, an embodiment of a wrist having axially slidingmembers may have integrated cables and sliding members, for examplewhereby the sliding members are integrally formed around the cables(e.g., by extrusion) as integrated sliding elements, or whereby anactuation mechanism couples to the proximal ends of the sliding members,the sliding members transmitting forces directly to the distal end ofthe wrist.

FIG. 13 shows a wrist 130 having a plurality of axial members 132 thatare typically made of a flexible plastic material. The axial members 132may be co-extruded over the cables 134, so that the cables can be metaland still be isolated. The axial members 132 may be connected to eachother by an axial tongue and groove connection 136 to form a tubularwrist 130. The axial members 132 may be allowed to slide relative toeach other during bending of the wrist 130 in pitch and yaw. The wrist130 is similar to the wrist 80 of FIG. 8 but has a slightly differentconfiguration and the components have different shapes.

D. Wrist Having Overlapping Axial Spring Members

FIGS. 10 and 11 show a wrist 100 formed by a plurality of axial springs102 arranged around a circumference to form a tubular wrist 100. Thesprings 102 are coil springs wound in the same direction or, morelikely, in opposite directions. A cable 104 extends through the overlapregion of each pair of adjacent springs 102, as more clearly seen inFIG. 11. Due to the overlap, the solid height of the wrist 100 would betwice the solid height of an individual spring 102, if the wrist isfully compressed under cable tension. The springs 102 are typicallypreloaded in compression so that the cables are not slack and toincrease wrist stability.

In one alternative, the springs are biased to a fully compressed solidheight state by cable pre-tension when the wrist is neutral or in anunbent state. A controlled, coordinated decrease in cable tension orcable release on one side of the wrist permits one side to expand sothat the springs on one side of the wrist 100 expand to form the outsideradius of the bent wrist 100. The wrist is returned to the straightconfiguration upon reapplication of the outside cable pulling force.

In another alternative, the springs are biased to a partially compressedstate by cable pre-tension when the wrist is neutral or in an unbentstate. A controlled, coordinated increase in cable tension or cablepulling on one side of the wrist permits that side to contract so thatthe springs on one side of wrist 100 shorten to form the inside radiusof the bent wrist 100. Optionally this can be combined with a release oftension on the outside radius, as in the first alternative above. Thewrist is returned to the straight configuration upon restoration of theoriginal cable pulling force.

E. Wrist Having Wave Spring Members

FIG. 12 shows a wrist in the form of a wave spring 120 having aplurality of wave spring segments or components 122 which are stacked orwound to form a tubular, wave spring wrist 120. In one embodiment, thewave spring is formed and wound from a continuous piece of flat wire ina quasi-helical fashion, wherein the waveform is varied each cycle sothat high points of one cycle contact the low points of the next. Suchsprings are commercially available, for instance, from the SmalleySpring Company. Holes are formed in the wave spring wrist 120 to receiveactuation cables. Alternatively, a plurality of separate disk-like wavespring segments may be strung bead-fashion on the actuator cables(retained by the cables or bonded to one another).

The wave spring segments 122 as illustrated each have two opposite highpoints and two opposite low points which are spaced by 90 degrees. Thisconfiguration facilitates bending in pitch and yaw. Of course, the wavespring segments 122 may have other configurations such as a more densewave pattern with additional high points and low points around thecircumference of the wrist 120.

F. Wrist Having Disks with Spherical Mating Surfaces

FIG. 14 shows several segments or disks 142 of the wrist 140. Aninterior spring 144 is provided in the interior space of the disks 142,while a plurality of cables or wires 145 are used to bend the wrist 140in pitch and yaw. The disks 142 are threaded or coupled onto the innerspring 144, which acts as a lumen for pulling cables for an endeffector. The inner spring 144 provides axial stiffness, so that theforces applied through the pulling cables to the end effector do notdistort the wrist 140. In alternative embodiments, stacked solid spacerscan be used instead of the spring 144 to achieve this function. Thedisks 142 each include a curved outer mating surface 146 that mates witha curved inner mating surface 148 of the adjacent disk. FIG. 15illustrates bending of the wrist 140 with associated relative rotationbetween the disks 142. The disks 142 may be made of plastic or ceramic,for example. The friction between the spherical mating surfaces 146, 148preferably is not strong enough to interfere with the movement of thewrist 140. One way to alleviate this potential problem is to select anappropriate interior spring 144 that would bear some compressive loadingand prevent excessive compressive loading on the disks 142 duringactuation of the cables 145 to bend the wrist 140. The interior spring144 may be made of silicone rubber or the like. An additional siliconmember 150 may surround the actuation cables as well. In alternateembodiments, the separate disks 142 may be replaced by one continuousspiral strip.

In alternate embodiments, each cable in the wrist 160 may be housed in aspring wind 162 as illustrated in FIGS. 16 and 17. An interior spring164 is also provided. The disks 170 can be made without the annularflange and holes to receive the cables (as in the disks 142 in FIGS. 14and 15). The solid mandrel wires 172 inside of the spring winds 162 canbe placed in position along the perimeters of the disks 170. A centerwire mandrel 174 is provided in the middle for winding the interiorspring 164. The assembly can be potted in silicone or the like, and thenthe mandrel wires 172, 174 can be removed. Some form of cover or thelike can be used to prevent the silicone from sticking to the sphericalmating surfaces of the disks 170. The small mandrel springs 172 will bewound to leave a small gap (instead of solid height) to provide room forshrinking as the wrist 160 bends, The silicone desirably is bondedsufficiently well to the disks 170 to provide torsional stiffness to thebonded assembly of the disks 170 and springs 172, 174. The insulativesilicone material may serve as cautery insulation for a cautery toolthat incorporates the wrist 160.

G. Wrist Having Disks Separated by Elastomer Members

FIG. 18 shows a wrist 180 having a plurality of disks 182 separated byelastomer members 184. The elastomer members 184 may be annular members,or may include a plurality of blocks distributed around thecircumference of the disks 182. Similar to the wrist 140 of FIG. 14, aninterior spring 186 is provided in the interior space of the disks 182and the elastomer members 184, while a plurality of cables or wires 188are used to bend the wrist 180 in pitch and yaw. The disks 182 arethreaded or coupled onto the inner spring 184, which acts as a lumen forpulling cables for an end effector. The inner spring 184 provides axialstiffness, so that the forces applied through the pulling cables to theend effector do not distort the wrist 180. The configuration of thiswrist 180 is more analogous to a human spine than the wrist 140. Theelastomer members 184 resiliently deform to permit bending of the wrist180 in pitch and yaw. The use of the elastomer members 184 eliminatesthe need for mating surfaces between the disks 182 and the associatedfrictional forces.

H. Wrist Having Alternating Ribs Supporting Disks for Pitch and YawBending

FIG. 19 shows a wrist 190 including a plurality of disks 192 supportedby alternating beams or ribs 194, 196 oriented in orthogonal directionsto facilitate pitch and yaw bending of the wrist 190. The wrist 190 maybe formed from a tube by removing cut-outs between adjacent disks 192 toleave alternating layers of generally orthogonal ribs 194, 196 betweenthe adjacent disks 192. The disks 192 have holes 198 for actuationcables to pass therethrough. The disks 192 and ribs 194, 196 may be madeof a variety of material such as steel, aluminum, nitinol, or plastic.In an alternate embodiment of the wrist 200 as illustrated in FIG. 20,the disks 202 include slots 204 instead of holes for receiving thecables. Such a tube is easier to extrude than a tube with holes forpassing through cables. A spring 206 is wound over the disks 202 tosupport the cables.

In FIG. 21, the wrist 210 includes disks 212 supported by alternatingbeams or ribs 214, 216 having cuts or slits 217 on both sides of theribs into the disks 212 to make the ribs 214, 216 longer than thespacing between the disks 212. This configuration may facilitate bendingwith a smaller radius of curvature than that of the wrist 190 in FIG. 19for the same wrist length, or achieve the same radius of curvature usinga shorter wrist. A bending angle of about 15 degrees between adjacentdisks 212 is typical in these embodiments. The disks 212 have holes 218for receiving actuation cables.

I. Wrist Employing Thin Disks Distributed Along Coil Spring

FIG. 22 shows a portion of a wrist 220 including a coil spring 222 witha plurality of thin disks 224 distributed along the length of the spring222. Only two disks 224 are seen in the wrist portion of FIG. 22,including 224A and 224B which are oriented with tabs 226 that areorthogonal to each other, as illustrated in FIGS. 23 and 24. The spring222 coils at solid height except for gaps which are provided forinserting the disks 224 therein. The spring 222 is connected to thedisks 224 near the inner edge and the tabs 226 of the disks 224. Thedisks 224 may be formed by etching, and include holes 228 for receivingactuation cables. The tabs 226 act as the fulcrum to allow the spring222 to bend at certain points during bending of the wrist 220 in pitchand yaw. The disks 224 may be relatively rigid in some embodiments, butmay be flexible enough to bend and act as spring elements during bendingof the wrist 220 in other embodiments. A silicone outer cover may beprovided around the coil spring 222 and disks 224 as a dielectricinsulator. In addition, the spring 222 and disks 224 assembly may beprotected by an outer structure formed, for example, from outer piecesor armor pieces 250 FIGS. 25 and 26. Each armor piece 250 includes anouter mating surface 252 and an inner mating surface 254. The outermating surface 252 of one armor piece 250 mates with the inner matingsurface 254 of an adjacent armor piece 250. The armor pieces 250 arestacked along the length of the spring 222, and maintain contact as theyrotate from the bending of the wrist 220.

J. Wrist Having Outer Braided Wires

The flexible wrist depends upon the stiffness of the various materialsrelative to the applied loads for accuracy. That is, the stiffer thematerials used and/or the shorter the length of the wrist and/or thelarger diameter the wrist has, the less sideways deflection there willbe for the wrist under a given surgical force exerted. If the pullingcables have negligible compliance, the angle of the end of the wrist canbe determined accurately, but there can be a wandering or sidewaysdeflection under a force that is not counteracted by the cables. If thewrist is straight and such a force is exerted, for example, the wristmay take on an S-shape deflection. One way to counteract this is withsuitable materials of sufficient stiffness and appropriate geometry forthe wrist. Another way is to have half of the pulling cables terminatehalfway along the length of the wrist and be pulled half as far as theremaining cables, as described in U.S. patent application Ser. No.10/187,248. Greater resistance to the S-shape deflection comes at theexpense of the ability to withstand moments. Yet another way to avoidthe S-shape deflection is to provide a braided cover on the outside ofthe wrist.

FIG. 27 shows a wrist 270 having a tube 272 that is wrapped in outerwires 274. The wires 274 are each wound to cover about 360 degreerotation between the ends of the tube 272. To increase the torsionalstiffness of the wrist 270 and avoid S-shape deflection of the wrist270, the outer wires 274 can be wound to form a braided covering overthe tube 272. To form the braided covering, two sets of wires includinga right-handed set and a left-handed set (i.e., one clockwise and onecounter-clockwise) are interwoven. The weaving or plaiting prevents theclockwise and counterclockwise wires from moving radially relative toeach other. The torsional stiffness is created, for example, becauseunder twisting, one set of wires will want to grow in diameter while theother set shrinks. The braiding prevents one set from being differentfrom the other, and the torsional deflection is resisted. It isdesirable to make the lay length of the outer wires 274 equal to thelength of the wrist 270 so that each individual wire of the braid doesnot have to increase in length as the wrist 270 bends in a circular arc,although the outer wires 274 will need to slide axially. The braid willresist S-shape deflection of the wrist 270 because it would require theouter wires 274 to increase in length. Moreover, the braid may alsoprotect the wrist from being gouged or cut acting as armor. If thebraided cover is non-conductive, it may be the outermost layer and actas an armor of the wrist 270. Increased torsional stiffness andavoidance of S-shape deflection of the wrist can also be accomplished bylayered springs starting with a right hand wind that is covered by aleft hand wind and then another right hand wind. The springs would notbe interwoven.

K. Wrist Cover

The above discloses some armors or covers for the wrists. FIGS. 28 and29 show additional examples of wrist covers. In FIG. 28, the wrist cover280 is formed by a flat spiral of non-conductive material, such asplastic or ceramic. When the wrist is bent, the different coils of thespiral cover 280 slide over each other. FIG. 29 shows a wrist cover 290that includes bent or curled edges 292 to ensure overlap betweenadjacent layers of the spiral. To provide torsional stiffness to thewrist, the wrist cover 300 may include ridges or grooves 302 orientedparallel to the axis of the wrist. The ridges 302 act as a spline fromone spiral layer to the next, and constitute a torsional stabilizer forthe wrist. Add discussion of nitinol laser cover configured like stents.

Thus, FIGS. 1-30 illustrate different embodiments of a surgicalinstrument with a flexible wrist. Although described with respect tocertain exemplary embodiments, those embodiments are merely illustrativeof the invention, and should not be taken as limiting the scope of theinvention. Rather, principles of the invention can be applied tonumerous specific systems and embodiments.

FIGS. 31-34 illustrate different embodiments of a surgical instrument(e.g., an endoscope and others) with a flexible wrist to facilitate thesafe placement and provide visual verification of the ablation catheteror other devices in Cardiac Tissue Ablation (CTA) treatments. Some partsof the invention illustrated in FIGS. 31-34 are similar to theircorresponding counterparts in FIGS. 1-30 and like elements are soindicated by primed reference numbers. Where such similarities exist,the structures/elements of the invention of FIGS. 31-34 that are similarand function in a similar fashion as those in FIGS. 1-30 will not bedescribed in detail again. It should be clear that the present inventionis not limited in application to CTA treatments but has other surgicalapplications as well. Moreover, while the present invention finds itsbest application in the area of minimally invasive robotic surgery, itshould be clear that the present invention can also be used in anyminimally invasive surgery without the aid of surgical robots.

L. Articulate/Steerable and Endoscope

Reference is now made to FIG. 31 which illustrates an embodiment of anendoscope 310 used in robotic minimally invasive surgery in accordancewith the present invention. The endoscope 310 includes an elongate shaft14′. A flexible wrist 10′ is located at the working end of shaft 14′. Ahousing 53′ allows surgical instrument 310 to releasably couple to arobotic arm (not shown) located at the opposite end of shaft 14′. Anendoscopic camera lens is implemented at the distal end of flexiblewrist 10′. A lumen (not shown) runs along the length of shaft 14′ whichconnects the distal end of flexible wrist 10′ with housing 53′. In a“fiber scope” embodiment, imaging sensor(s) of endoscope 310, such asCharge Coupled Devices (CCDs), may be mounted inside housing 53′ withconnected optical fibers running inside the lumen along the length ofshaft 14′ and ending at substantially the distal end of flexible wrist10′. The CCDs are then coupled to a camera control unit via connector314 located at the end of housing 53′. In an alternate “chip-on-a-stick”embodiment, the imaging sensor(s) of endoscope 310 may be mounted at thedistal end of flexible wrist 10′ with either hardwire or wirelesselectrical connections to a camera control unit coupled to connector 314at the end of housing 53′. The imaging sensor(s) may be two-dimensionalor three-dimensional.

Endoscope 310 has a cap 312 to cover and protect endoscope lens 314 atthe tip of the distal end of flexible wrist 10′. Cap 312, which may behemispherical, conical, etc., allows the instrument to deflect awaytissue during maneuvering inside/near the surgery site. Cap 312, whichmay be made out of glass, clear plastic, etc., is transparent to allowendoscope 310 to clearly view and capture images. Under certainconditions that allow for clear viewing and image capturing, cap 312 maybe translucent as well. In an alternate embodiment, cap 312 isinflatable (e.g., to three times its normal size) for improved/increasedviewing capability of endoscope 310. An inflatable cap 312 may be madefrom flexible clear polyethylene from which angioplasty balloons aremade out or a similar material. In so doing, the size of cap 312 andconsequently the minimally invasive surgical port size into whichendoscope 310 in inserted can be minimized. After inserting endoscope310 into the surgical site, cap 312 can then be inflated to provideincreased/improved viewing. Accordingly, cap 312 may be coupled to afluid source (e.g., saline, air, or other gas sources) to provide theappropriate pressure for inflating cap 312 on demand.

Flexible wrist 10′ has at least one degree of freedom freedom to allowendoscope 310 to articulate and maneuver easily around internal bodytissues, organs, etc. to reach a desired destination (e.g., epicardialor myocardial tissue). Flexible wrist 10′ may be any of the embodimentsdescribed relative to FIGS. 1-30 above. Housing 53′ also houses a drivemechanism for articulate the distal portion of flexible wrist 10′ (whichhouses the endoscope). The drive mechanism may be cable-drive,gear-drive, belt drive, or other types of mechanism. An exemplary drivemechanism and housing 53′ are described in U.S. Pat. No. 6,394,998 whichis incorporated by reference. That exemplary drive mechanism providestwo degrees of freedom for flexible wrist 10′ and allows shaft 14′ torotate around an axis along the length of the shaft. In a CTA procedure,the articulate endoscope 310 maneuvers and articulates around internalorgans, tissues, etc. to acquire visual images of hard-to-see and/orhard-to-reach places. The acquired images are used to assist in theplacement of the ablation catheter on the desired cardiac tissue. Thearticulate endoscope may be the only scope utilized or it may be used asa second or third scope to provide alternate views of the surgical siterelative to the main image acquired from a main endoscope.

M. Articulating Endoscope with Releasably Attached AblationCatheter/Device

As an extension of the above articulate endoscope, a catheter may bereleasably coupled to the articulate endoscope to further assist in theplacement of the ablation catheter on a desired cardiac tissue. FIG. 32illustrates catheter 321 releasably coupled to endoscope 310 by a seriesof releasable clips 320. Other types of releasable couplings (mechanicalor otherwise) can also be used and are well within the scope of thisinvention. As shown in FIG. 32, clips 320 allow ablation device/catheter321 to be releasably attached to endoscope 310 such that ablationdevice/catheter 321 follows endoscope 310 when it is driven, maneuvered,and articulated around structures (e.g., pulmonary vessels, etc.) toreach a desired surgical destination in a CTA procedure. When articulateendoscope 310 and attached ablation device/catheter 321 reach thedestination, catheter 321 is held/kept in place, for example by anotherinstrument connected to a robot arm, while endoscope 310 is releasedfrom ablation device/catheter 321 and removed. In so doing, images takenby endoscope 310 of hard-to-see and/or hard-to-reach places duringmaneuvering can be utilized for guidance purposes. Moreover, theendoscope's articulation further facilitates the placement of ablationdevice/catheter 321 on hard-to-reach cardiac tissues.

In an alternate embodiment, instead of a device/catheter itself,catheter guide 331 may be realeasably attached to endoscope 310. Asillustrated in FIG. 33, catheter guide 331 is then similarly guided byarticulate endoscope 310 to a final destination as discussed above. Whenarticulate endoscope 310 and attached catheter guide 331 reach thedestination, catheter guide 331 is held/kept in place, for example byanother instrument connected to a robot arm, while endoscope 310 isreleased from catheter guide 331 and removed. An ablationcatheter/device can then be slid into place using catheter guide 331 atits proximal end 332. In one embodiment, catheter guide 331 utilizesreleaseably couplings like clips 320 to allow the catheter to be slidinto place. In another embodiment, catheter guide 331 utilizes a lumenbuilt in to endoscope 310 into which catheter guide 331 can slip and beguided to reach the target.

N. Articulating Instrument with Lumen to Guide Endoscope

In yet another embodiment, instead of having an articulate endoscope, anend effector is attached to the flexible wrist to provide the instrumentwith the desired articulation. This articulate instrument was describedfor example in relation to FIGS. 1-2 above. However, the articulateinstrument further include a lumen (e.g., a cavity, a working channel,etc.) that runs along the shaft of the instrument into which an externalendoscope can be inserted and guided toward the tip of the flexiblewrist. This embodiment achieves substantially the same functions of thearticulating endoscope with a releasably attached ablationcatheter/device or with a releasably attached catheter guide asdescribed above. The difference is that the ablation catheter/device isused to drive and maneuver with the endoscope being releasably attachedto the ablation device through insertion into a built-in lumen. With thebuilt-in lumen, the releasable couplings (e.g., clips) are eliminated.

Reference is now made to FIG. 34 illustrating a video block diagramillustrating an embodiment of the video connections in accordance to thepresent invention. As illustrated in FIG. 34, camera control unit 342controls the operation of articulate endoscope 310 such as zoom-in,zoom-out, resolution mode, image capturing, etc. Images captured byarticulate endoscope 310 are provided to camera control unit 342 forprocessing before being fed to main display monitor 343 and/or auxiliarydisplay monitor 344. Other available endoscopes 345 in the system, suchas the main endoscope and others, are similarly controlled by their owncamera control units 346. The acquired images are similarly fed to maindisplay monitor 343 and/or auxiliary display monitor 344. Typically,main monitor 343 displays the images acquired from the main endoscopewhich may be three-dimensional. The images acquired from articulateendoscope 310 (or an endoscope inserted into the lumen of the articulateinstrument) may be displayed on auxiliary display monitor 344.Alternately, the images acquired from articulate endoscope 310 (or anendoscope inserted into the lumen of the articulate instrument) can bedisplayed as auxiliary information on the main display monitor 343 (seea detail description in n U.S. Pat. No. 6,522,906 which is hereinincorporated by reference).

The articulate instruments/endoscopes described above may be covered byan optional sterile sheath much like a condom to keep the articulateinstrument/endoscope clean and sterile thereby obviating the need tomake these instruments/endoscopes sterilizable following use in asurgical procedures. Such a sterile sheath needs to be translucent toallow the endoscope to clearly view and capture images. Accordingly, thesterile sheath may be made out of a latex-like material (e.g., Kraton®,polyurethane, etc.). In one embodiment, the sterile sheath and cap 312may be made from the same material and joined together as one piece. Cap312 can then be fastened to shaft 14′ by mechanical or other type offasteners.

Hence, FIGS. 31-34 illustrate different embodiments of a surgicalinstrument (e.g., an endoscope and others) with a flexible wrist tofacilitate the safe placement and provide visual verification of theablation catheter or other devices in Cardiac Tissue Ablation (CTA)treatments. Although described with respect to certain exemplaryembodiments, those embodiments are merely illustrative of the invention,and should not be taken as limiting the scope of the invention. Rather,principles of the invention can be applied to numerous specific systemsand embodiments.

FIGS. 35-37 illustrate an articulate/steerable and swappable endoscopein accordance to the present invention. Some parts of the inventionillustrated in FIGS. 35-37 are similar to their correspondingcounterparts in FIGS. 1-34 as well as in other figures described in theincorporation by references and like elements are so indicated bydouble-primed reference numbers. Where such similarities exist, thestructures/elements of the invention of FIGS. 35-37 that are similar andfunction in a similar fashion as those in FIGS. 1-34 will not bedescribed in detail again.

O. Articulate/Steerable and Swappable Endoscope

Reference is now made to FIG. 35 which illustrates an embodiment of anarticulate and swappable endoscope 310″ used in robotic minimallyinvasive surgery in accordance with the present invention. The endoscope310″ includes an elongate shaft 14″. A flexible wrist 10″ is located atthe working end of shaft 14″. A housing 53″ allows surgical instrument310 to releasably couple to a robotic arm (not shown), such as thatdescribed in U.S. Pat. Nos. 6,331,181 and 6,394,998, located at theopposite end of shaft 14″. Unlike the robotic arm described in U.S. Pat.No. 6,451,027 which is designed to hold a more heavy and bulky endoscopecamera, the robotic arm described in U.S. Pat. Nos. 6,331,181 and6,394,998, which are incorporated by reference in their entirety, isdesigned for lighter surgical instruments. To achieveinterchangeability/swappability, a robotic arm design similar to thatdescribed in U.S. Pat. Nos. 6,331,181 and 6,394,998 is to be used forall the arms of the surgical robot. In other words, instead of using arobotic arm designed primarily to carry a surgical endoscope, auniversal/standard robotic arm designed for a smaller load is used tocarry all types of surgical instruments including a surgical endoscope.In so doing, a surgical endoscope can be mounted onto any of theplurality of surgical robotic arms of the surgical robot therebyallowing the surgical endoscope to be swapped between different surgicalarms as required during a procedure. As a result, surgeons can nowexchange the endoscope between ports as typically occurred inconventional laparoscopy. The exchange can easily be performed byreleasing and detaching the endoscope from one arm and then attachingand locking the endoscope to a different arm which allows the endoscopeto be inserted into a different surgical port in the patient's body.Additionally, the mechanical and architectural design of the roboticsurgical system can be simplified because it is no longer necessary toaccommodate different types of instrument arms.

To achieve this objective, the endoscope needs to be made smaller andlighter. In accordance to the present invention, an endoscopic cameralens is implemented at the distal end of flexible wrist 10″. A lumen(not shown) runs along the length of shaft 14″ which connects the distalend of flexible wrist 10″ with housing 53″. In the preferred“chip-on-a-stick” embodiment, the imaging sensor(s) of endoscope 310″may be mounted at the distal end of flexible wrist 10′ with eitherhardwire or wireless electrical connections to a camera control unitcoupled to connector 314″ at the end of housing 53″. The imagingsensor(s) may be two-dimensional (2D) or three-dimensional (3D). Somesophisticated signal processing technology can be used to derive a 3Dimage from a 2D imaging sensor(s). Some exemplary commercially availablechip-on-a-stick endoscope solutions include Olympus America, Inc. ofMelville, N.Y., Visionsense of Petach Tiqua, Israel, and others. Such achip-on-a-stick embodiment may reduce the size of the endoscope to afraction of its former size and reduce its weight by an order ofmagnitude. Accordingly, the size and weight of the endoscope no longerpresents difficulty in mounting/dismounting as well as maneuvering theendoscope. In an alternate “fiber scope” embodiment, imaging sensor(s)of endoscope 310″, such as Charge Coupled Devices (CCDs), may be mountedinside housing 53″ with connected optical fibers running inside thelumen along the length of shaft 14″ and ending at substantially thedistal end of flexible wrist 10″.

Endoscope 310″ may have a cap 312″ to cover and protect endoscope lens314″ at the tip of the distal end of flexible wrist 10″. Cap 312″, whichmay be hemispherical, conical, etc., allows the instrument to deflectaway tissue during maneuvering inside/near the surgery site. Cap 312″,which may be made out of glass, clear plastic, etc., is transparent toallow endoscope 310″ to clearly view and capture images. Under certainconditions that allow for clear viewing and image capturing, cap 312″may be translucent as well. In an alternate embodiment, cap 312″ isinflatable (e.g., to three times its normal size) for improved/increasedviewing capability of endoscope 310″. An inflatable cap 312″ may be madefrom flexible clear polyethylene from which angioplasty balloons aremade out or a similar material. In so doing, the size of cap 312″ andconsequently the minimally invasive surgical port size into whichendoscope 310″ is inserted can be minimized. After inserting endoscope310″ into the surgical site, cap 312″ can then be inflated to provideincreased/improved viewing. Accordingly, cap 312″ may be coupled to afluid source (e.g., saline, air, or other gas sources) to provide theappropriate pressure for inflating cap 312″ on demand.

Flexible wrist 10″ provides additional degrees of freedom to allowendoscope 310 to articulate and maneuver easily around internal bodytissues, organs, etc. to reach a desired destination (e.g., epicardialor myocardial tissue). Flexible wrist 10″ may be any of the embodimentsdescribed relative to FIGS. 1-30 above, or described in U.S. Pat. No.6,817,974, other embodiments having a plurality of joints, etc. Housing53″ also houses a drive mechanism for articulating the distal portion offlexible wrist 10″ (which houses the endoscope). The drive mechanism maybe cable-drive, gear-drive, belt drive, or other types of mechanism. Anexemplary drive mechanism and housing 53″ are described in U.S. Pat. No.6,394,998 which is incorporated by reference. That exemplary drivemechanism provides two degrees of freedom for flexible wrist 10″ (pitchand yaw) and allows shaft 14″ to rotate around an axis along the lengthof the shaft (roll). The pitch and yaw degrees of freedom, which are thebending of wrist 10″ just proximal to the tip of the endoscope lensabout an imaginary horizontal axis and vertical axis, respectively) arein addition to an insertion/extraction motion (e.g., x, y, and zCartesian motion) and instrument shaft rotation (e.g., roll motion). Assuch, endoscope 310″ is provided with the same degrees of freedom asother robotic surgical instruments (e.g., graspers, etc.) which pose thequestion of how to give surgeons intuitive methods to control theendoscope's additional degrees of freedom.

P. Camera-Reference Control Paradigm of Slave Instruments

It is desirable to provide surgeons with intuitive methods to controlcomplex surgical robots. As a surgeon becomes engrossed in a delicateand complex surgical procedure, he needs not be aware of how a surgicalrobot performs its duties and perhaps sometimes forgets that he is usinga robot to perform the surgical procedure due to the intuitiveness ofthe way the robot manipulates and performs its tasks as directed by thesurgeon. As a simplistic exemplary illustration of intuitive versuscounter-intuitive, consider FIG. 36 which illustrates that when theendoscope has a level gaze pointed straight ahead, there is nodifference between world-reference (a.k.a. image-reference) control andcamera-reference (e.g., the frame attached to the distal tip of theendoscope) control. However, when the camera rotates, for example, 90degrees clockwise, basing the slave instrument movement in the camerareference frame makes a big difference in keeping the instrument motionintuitive to the surgeon because if the instrument is based in aworld-reference, a left-right motion of the surgeon's hand would appearto cause an up-down motion of the surgical instrument. Accordingly, U.S.Pat. No. 6,364,888 (hereinafter the '888 patent) and U.S. Pat. No.6,424,885 (hereinafter the '885 patent), which are incorporated byreference in its entirety, describe controlling all slave instrumentmotions and orientations in the endoscope camera-reference frame toprovide such intuitiveness. However, the endoscope described in the '888patent and '885 patent does not have the pitch and yaw degrees offreedom as the endoscope in the present invention. Hence, the challengesand consequently paradigm associated with these degrees of freedom areunexpected.

The first of such paradigm is discussed next. When the endoscope inaccordance to the present invention undergoes a pitching or yawingmotion, if the image is viewed from the camera-reference frame, the viewmay be counterintuitive to a surgeon. This is because if the endoscopeis pitched up, the view from the camera-reference frame appears to be alook-down rather than a look-up view that the surgeon intuitivelyexpects. If the endoscope is pitched down, the view from thecamera-reference frame appears to be a look-up rather than a look-downthat the surgeons intuitively expects. Similarly, if the endoscope isyawed left, the view from the camera appears to be a look-right ratherthan a look-left that the surgeons intuitively expects. If the endoscopeis yawed right, the view from the camera appears to be a look-leftrather than a look-right that the surgeon intuitively expects. Suchcounter-intuitiveness is unexpected and requires a change of referenceframe for the slave surgical instruments from a camera-reference frameto that of a world/image-reference for the endoscope's pitching andyawing motion to retain the intuitiveness desired in the presentinvention. The reference frame for the slave surgical instrumentsremains the camera-reference frame for all other endoscope's degrees offreedom (e.g., x, y, and z Cartesian insertion/extraction motion andinstrument shaft roll motion) in the present invention. In other words,the reference frame for the additional degrees of freedom is decoupledfrom that for the traditional degrees of freedom associated with asurgical robotic endoscope. Nevertheless, it is to be appreciated thatin accordance to the present invention, for some applications it may beadvantageous to afford a choice between a camera-reference frame and anworld-reference frame for controlling each and any of the six degrees offreedom of the articulating/steerable and swappable endoscope. In otherwords, any or all of the six degrees of freedom of thearticulating/steerable and swappable endoscope can be controlled ineither the camera reference frame or the world reference frame.

In a master-slave surgical robotic system such as the da Vinci® system,if any (or all) of the six degrees of freedom is controlled in thecamera-reference frame, then the reference frame is changing along withthe camera movement in terms of position and/or orientation. In otherwords, the master (i.e., surgeon's eye) relationship relative to theslave (e.g., endoscope camera) is changing due to the camera's movementwhich may adversely effect the intuitiveness of the surgeon's perceptionrelative to his input unless such change is compensated. Thiscompensation is performed by repositioning the master input devicethrough control transformations. More specifically, the master/eyetransform is adjusted to match the changing slave/camera transform.Preferably, such master alignment compensation is carried outcontinuously and incrementally (via incremental transforms) duringcamera control (i.e., in or near real-time) rather than making largercompensation following camera control (i.e., sequential) because theassociated lag time is minimized. It is appreciated that such masteralignment compensation is not required in non-flexible and non-steerableendoscopic systems or in the case in which all six degrees of freedomare controlled in the world-reference frame because the reference frameis constant in these cases.

A master input device such as that described in U.S. Pat. No. 6,714,839,which is herein incorporated by reference in its entirety, can bemaneuvered with at least six (6) degrees of freedom. If a separatemaster input device is used for a user's left and right hand as shown inFIG. 38, a total of at least twelve (12) degrees of freedom areavailable from virtually combining the two master input devices forcontrolling the endoscope camera's positions and orientations as well asfunctions such as focus, aperture, etc. FIG. 38 illustrates the twomaster input devices virtually combined to operate in a similar fashionto a bicycle handle bar. Since the camera can move along as well asrotate about the X, Y, and Z axes, six (6) degrees of freedom from thevirtually combined master input devices are required to command thesesix positions and orientations using either velocity (a.k.a. rate) orposition control. Additionally, three (3) degrees of freedom from thevirtually combined master input devices are needed to implement/handlegeometric constraints of the combined master input devices. Accordingly,at least three (3) spare degrees of freedom remain available to commandother camera functions (e.g., focus, aperture, etc.). In a preferredembodiment, the three degrees of freedom use to command these othercamera functions are: twisting the handle bar (i.e., two master inputdevices), bending the handle bar, and rolling each master input devicein opposite directions.

It should be clear to person of ordinary skill in the art that anymathematical changes (e.g., reference frame position/orientationtransformation) as well as control system changes (e.g., controlalgorithm) associated with such a frame of reference change can bederived and implemented in view of the relevant detailed descriptions ofthe '888 patent and '885 patent. Accordingly, for the sake of brevityand clarity no additional discussion on this is provided herein.

Q. Point of Rotation for Pitch and Yaw Motion

A second control paradigm involves the selection of a point of rotationfor the articulating/steerable and swappable endoscope. The point ofrotation is a point about which the reference frame of an endoscopicimage view rotates. This point of rotation is selected to provide asense of intuitiveness as well as the most optimal view of the surgicalsite for surgeons. For the articulating and swappable endoscope inaccordance to the present invention, the additional pitch and yawmotions (whether individually or both simultaneously) of the camera lensin combination with a properly selected point of rotation can be used tomaneuver the endoscope (possibly in combination with other degrees offreedom) to provide an orbital view of an anatomy (similar to the viewobserved by a satellite orbiting a planet) inside a surgical siterelative to the camera-reference frame. It is noted that such aselection of a point of rotation is not required for traditional roboticsurgical endoscopes (e.g., an endoscope without the pitch and yawmotions) and is therefore not anticipated. The point of rotationcandidates include: an assumed center of the surgical site which may bea point within the maximum working range of an endoscope (e.g.,approximately thirty-eight (38) mm from the distal tip of an Olympusendoscope), a point in the proximate area of flexible wrist 10″, theendoscope surgical site entry point, etc.

Reference is now made to FIG. 37 illustrating the different potentialpoints of rotation for endoscope 310″ in accordance to the presentinvention. As shown in FIG. 37, endoscope 310″ has been inserted intoport 371 at a surgical site around organ 372. Point 373 is the assumedcenter, point 374 is the point adjacent to or on flexible wrist 10″, andpoint 375 is the point at which endoscope 310″ enters the surgery site.

The assumed center point of rotation may be the most logical becausemost activities in a surgical site will likely occur in the proximatearea surrounding the tip of the endoscope and given the six degrees offreedom of the articulating/steerable endoscope of the present inventiontogether with zooming capability, minor adjustments can be made quicklyto obtain the desired optimal view. However, there is a drawback in suchselection involving the over-active motion associated with the proximalend (back end) of endoscope 310″ and more significantly the robot armthat the endoscope is realeasably coupled to when a pitching and/oryawing motion of the camera lens is made. The over-active motion of therobot arm carrying endoscope 310″ may be undesirable as it may get inthe way of other robot arms of the system all of which may be movingconcurrently during a procedure resulting in an arm collision.

Moving the point of rotation to the endoscope surgical site entry pointappears to attenuate robot arm motion because the distance between thepoint of rotation and the robot arm is greatly reduced (by reducing theamount of coupled rotation and translation motion) but also appears toproduce less optimal viewing images of the surgical site due to physicaland geometric constraints. In comparison, with the point of rotationbeing around the center of flexible wrist 10″, the distance between thepoint of rotation and the robot arm is reduced thereby the arm motion isalso attenuated but with improved viewing images due to fewer physicaland geometric constraints. Hence, a point about the center of flexiblewrist 10″ is the preferred point of rotation for the articulatingswappable endoscope of the present invention. An exemplaryimplementation of a point of rotation is provided in the '885 patentwhich describes the mapping of master control point to slave controlpoint.

The above-described arrangements of apparatus and methods are merelyillustrative of applications of the principles of this invention andmany other embodiments and modifications may be made without departingfrom the spirit and scope of the invention as defined in the claims. Thescope of the invention should, therefore, be determined not withreference to the above description, but instead should be determinedwith reference to the appended claims along with their full scope ofequivalents.

What is claimed is:
 1. A system comprising: a single manual input devicemovable along a master horizontal axis by an operator; a slave movablein pitch and yaw in response to movement of the single manual inputdevice, the slave comprising an articulate endoscope having a flexiblewrist, said endoscope further comprising a camera configured to acquirean image, the camera coupled to the distal end of the flexible wrist; adisplay configured to show the acquired image; and a processor couplingthe single manual input device to the slave, the processor programmed tomap movement along the master horizontal axis to slave movement in pitchaccording to a first transformation corresponding to a world-referenceframe, the processor further programmed to map movement along the masterhorizontal axis to slave movement in yaw according to a secondtransformation corresponding to a camera-reference frame.
 2. The systemof claim 1, wherein the acquired image is based on a reference framerotating around a point of rotation located proximal to the flexiblewrist.
 3. The system of claim 2, where the image is an orbital view. 4.The system of claim 1, further comprising a plurality of slave armassemblies, wherein a standard design is used for each of the pluralityof slave arm assemblies such that the endoscope may be releasablyswapped among the plurality of slave arm assemblies.
 5. The system ofclaim 1, wherein the single manual input device is further used tocontrol at least one function of the camera.
 6. The system of claim 1,wherein a master alignment compensation is carried out continuously andincrementally during a movement of the camera to maintain master-slaveintuitiveness between the input device and the camera.
 7. The system ofclaim 1, wherein at least one degree of freedom is position or velocitycontrolled.
 8. The system of claim 5, the at least one functioncomprising focus of the camera.
 9. The system of claim 5, the at leastone function comprising aperture of a lens of the camera.
 10. The systemof claim 7, wherein the at least one degree of freedom comprisesmovement in yaw or pitch.
 11. The system of claim 1, wherein aworld-reference frame is selected if the flexible wrist is moved by thesingle input device in a first degree of freedom, and wherein acamera-reference frame is selected if the flexible wrist is moved by thesingle input device in a second degree of freedom.
 12. The system ofclaim 11, the at least one slave further comprising a manipulator armcoupled to an end effector, the world-reference and camera-referenceframes defining distinct relationships between movement of the singleinput device and movement of the end effector.
 13. The system of claim12, wherein a world-reference frame is selected if the wrist is moved inpitch or yaw, and wherein a camera-reference frame is selected if thewrist is moved in a degree of freedom other than pitch or yaw.
 14. Thesystem of claim 1, wherein the image acquired by the camera is based ona reference frame rotating around an assumed center of a surgical site.15. The system of claim 1, wherein the image acquired by the camera isbased on a reference frame rotating around an entry point of the slaveinto a surgical site.
 16. The system of claim 1, the movement along themaster horizontal axis corresponding to a left and right movement of thesingle manual input device, the slave movement in yaw corresponding to aleft and right movement of the slave, the slave movement in pitchcorresponding to an up and down movement of the slave.
 17. The system ofclaim 1, wherein the world-reference frame is defined as being levelwith a gaze of the operator, and the camera-reference frame is definedas being attached to the camera.